Who is at fault for American Airlines flight 587?

Who is at fault for American Airlines flight 587? - 1

NTSB report on AA 587 spreads blame
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From the NTSB report of the accident:
The National Transportation Safety Board determines that the probable cause of this accident was the in-flight separation of the vertical stabilizer as a result of the loads beyond ultimate design that were created by the first officer's unnecessary and excessive rudder pedal inputs. Contributing to these rudder pedal inputs were characteristics of the Airbus A300-600 rudder system design and elements of the American Airlines Advanced Aircraft Maneuvering Program (AAMP).

As the airspeed increases the force the rudder exerts on the airframe also increase. Modern aircraft, therefore, must limit the rudder movement during cruise. The rudder limiter takes many forms: on a Boeing 767 full rudder pedal moment is available but the gain from the pedal movement decreases with increase in airspeed. The A300 limits the rudder pedal movement. On the A300 the pilot also has to apply about 25 lb. Of force just to get the rudder pedals to move. Once the pedals start to move, the force to move them becomes much less than 25 lb.

In September 1994 a US Air Flight 427 encountered wake turbulence from a preceding aircraft, rolled to the right and crash. At the time, it was believed that aggressive use of rudder could have recovered the aircraft, and all pilots were trained accordingly.

Shortly after takeoff AA587 encountered wake turbulence from a Japan Airlines 747 that took off two minutes earlier. At this time the AA587 was flying at over 200 knots and the rudder limiter started to limit the pedal movement. Upon encountering the wake turbulence, the co-pilot who was flying the plane, applied the rudder (I forgot which way.) Since he had to apply a substantial breakout force just to get the pedals to move, and the movement of the pedals was limited, he inadvertently applied full rudder. Apparently realizing that he applied too much rudder, he tried to correct by applying opposite rudder and again banged the pedals to the stops. In all aircraft went through 3 or 4 cycles of full rudder reversals. These rudder reversals exceeded the structural limits of the airframe and caused the vertical stabilizer to separate from the aircraft.

The official cause was the unnecessary and repeated rudder reversals applied by the copilot. The contributing cause was the aggressive use of rudder during wake turbulence situation given to the pilots at the time. Additionally, the A300-600R has a graphite epoxy composite vertical stabilizer. After the accident, several other A300-600Rs were found with composite material de-lamination and other manufacturing defects calling into question the strength of the vertical stabilizer structure.

Ultimately the pilots. The accident was likely preventable had the pilot stopped the rudder input and let the plane buffet itself out

Del